Brain Imaging Studies

One Brain, Two Selves

Authors: A. A. T. S. Reinders, , a, E. R. S. Nijenhuisb, A. M. J. Paansc, J. Korfa, A. T. M. Willemsenc and J. A. den Boera
Department of Biological Psychiatry, Groningen University Hospital, The Netherlands
12 May 2003

Abstract: Having a sense of self is an explicit and high-level functional specialization of the human brain. The anatomical localization of self-awareness and the brain mechanisms involved in consciousness were investigated by functional neuroimaging different emotional mental states of core consciousness in patients with Multiple Personality Disorder (i.e., Dissociative Identity Disorder (DID)). We demonstrate specific changes in localized brain activity consistent with their ability to generate at least two distinct mental states of self-awareness, each with its own access to autobiographical trauma-related memory. Our findings reveal the existence of different regional cerebral blood flow patterns for different senses of self. We present evidence for the medial prefrontal cortex (MPFC) and the posterior associative cortices to have an integral role in conscious experience.

Latest Research Findings shed light on Multiple Personality Disorder

12 November 2001

Scientists at Swinburne University have conducted a world first study into the psychiatric condition Dissociative Identity Disorder (DID), previously known as Multiple Personality Disorder.

Simply put DID patients may have a host personality that splits into personality fragments called alters. The research at Swinburne has shown clearly different brain patterns between the DID host and each personality or alter, a finding which could not be reproduced by professional actors emulating the child alters.

Original Study:

EEG coherence and dissociative Identity disorder: Comparing EEG coherence in DID hosts, alters, controls and acted alters

Authors: Annedore Hopper,  Joseph Ciorciari, Gillian Johnson, John Spensley, Alex Sergejew, Con Stough.
School of Biophysical Sciences and Electrical Engineering and the Brain Sciences Institute, Swinburne University of Technology, Victoria, AUSTRALIE
Journal of trauma & dissociation, 2002, vol. 3, no1, pp. 75-88 (1 p.3/4)

Abstract: This is the first study to apply EEG coherence analysis to the study of Dissociative Identity Disorder (DID). EEG coherence is argued to be an objective measure of cortical connectivity. Five DID patients were compared to five controls, who were professional actors. Fifteen dissociated DID alter states were studied, as were 15 alters simulated by the actor control participants. Comparisons of EEG coherence were made between DID participants and controls. Significant differences in EEG coherence were found in comparing DID host and alter personalities, with coherence found to be lower in the alter personalities. No significant differences were found in comparing DID host personalities and controls. The acted alters matched for age and gender, showed no significant differences in coherence compared to DID alter personalities. The results indicate that EEG coherence may be an objective measure of the neuronal cortical connectivity associated with DID.

Functional Magnetic Resonance Imaging of Personality Switches in a Woman with Dissociative Identity Disorder

Authors: Guochuan E. Tsai;  Donald Condie;  Ming-Ting Wu; I-Wen Chang
Harvard Review of Psychiatry, Volume 7, Issue 2 July 1999 , pages 119 – 122

(The following is not the article’s abstract, but a portion of a synopses written by student ML Kelly, 2005.)

The hippocampus and associated medial temporal areas are responsible for declarative memory (conscious memory of specific events), and the nigrostriatal system is responsible for nondeclarative memory (gradual, incremental learning of association). This study proposes that both types of memory are involved in personality switches in persons with DID.